textproduct: Albany

WHAT HAS CHANGED

Trended wind gusts today through Sunday to show more widespread gusts up to 30 - 40mph mainly in western New England, the northern and eastern Catskills, mid-Hudson Valley, Taconics and Capital District. This was based on forecast soundings and potential for sufficient boundary layer mixing to result in stronger winds at the surface.

KEY MESSAGES

1) Medium to high confidence in a Nor'easter this weekend resulting in breezy winds and periods of rain tonight through Monday. While any flooding impacts from rainfall should be limited to poor drainage and low lying areas, there is medium to high confidence that wind gusts exceeding 40 mph in Litchfield County, CT can down tree limbs and result in isolated power outages.

DISCUSSION

KEY MESSAGE 1...

Latest water vapor imagery shows our nor'easter continuing to intensify off the DelMarVA coast tonight as the latest RAP sfc analysis shows the sfc low down to 995hPa. Rain bands are rotating north and westward into New England with bands weakening as they extend into western New England and eastern NY. The coastal low will slowly drift northward today towards the southern New England coast with its favorable position in the equatorward exit region of a jet streak allowing it to deepen a few more millibars. While additional bands of showers will rotate from western New England into eastern NY today, forecast soundings suggests that showers will be mainly light as they overcome low and mid-level dry air. While only light and intermittent showers expected today, north-northeast winds will turn gusty, especially in western New England, the eastern Catskills, mid-Hudson Valley, Taconics, and parts of the Capital District. Forecast soundings show the dry air in the low-levels supporting sufficient boundary layer mixing this afternoon to allow strong winds aloft to mix to the sfc. Probabilistic guidance from the NBM shows a 50 to 75% chance for gust exceeding 30kts through sunset. Such winds can blow around unsecured outdoor objects and lead to downed tree limbs.

Heading into tonight, there is a strong consensus among the GEFS and EPS ensemble guidance that our nor'easter tracks further west/inland as a secondary shortwave from the Great Lakes/Ohio Valley phases with the parent cyclone this evening. This interaction and shift in track will allow moderate to heavy rain bands from our nor'easter to progress into eastern NY and western New England as very warm and moist air from the Atlantic continue to wrap into the storm, supporting areas of frontogenesis. There is even a low chance for some brief rumbles of thunder given weak elevated instability. With our sfc low remaining around 990hPa and its impressive 45-55kts jet in the 925-850hPa layer pushing inland, north-northeast winds remain gusty overnight with medium to high confidence that gusts will exceed 30kts in the aforementioned areas through Sunday. However, forecast soundings continue to show a sharp inversion that should prevent the strongest winds to mix down to the sfc. While there is a low to medium chance for wind gusts in the eastern Catskills to reach/slightly exceed 40kts, coverage and confidence in this is still too low to expand the wind advisory beyond Litchfield County. Confidence is the greatest chance here for wind gusts to reach 45kts resulting in downed tree limbs and isolated power outages. We will continue to keep a close eye on trends and can expand the wind advisory, if needed.

Besides the wind, bands of steady/moderate bands of rain from our nor'easter will rotate inland from New England into eastern New York tonight through Sunday night. Rain intensity should vary depending on the strengthen of a rain band but latest HREF guidance shows a 50 to 75% chance for 3-hrly rainfall amounts to exceed 0.50" from 09 - 18 UTC Sunday focused mainly from the Capital District and areas south and east. This time window will likely feature the heaviest rainfall rates and greatest potential for nuisance flooding in poor drainage and low-lying areas. We continue to have a River Flood Warning out for the Hudson River at Poughkeepsie given tidal flooding during its high tide cycle today and tonight. North- northeast winds will also support enhanced rainfall amounts in the east facing slopes of the northern and eastern Catskills, Taconics, southern Greens, and Berkshires. These areas also have the greatest chance (70-80%) for storm total rainfall amounts from 8PM Sat to 8PM Mon to exceed 2 inches with even a 50 to 60% chance for greater than 3 inches in the eastern Catskills and parts of NW CT. Otherwise, most of the region from the Capital District south and east should end up with between 1 and 2.50 inches of rain. Rainfall amounts will trend downwards heading north and west of the Capital District with the lowest amounts generally near or under 0.50" in the southwest Adirondacks as these areas should miss out on the heaviest rain bands. While our coastal low weakens by Monday as it becomes vertically stacked, a blocking pattern in place to its north and east will keep it stalled off the NJ coast. This will keep showers around into Monday before finally exiting by Monday night. Winds by this time should also weaken. Finally, weather conditions improve by Tuesday into the middle of next week.

AVIATION /07Z SATURDAY THROUGH WEDNESDAY/

Through 06 UTC/SUN...A BKN to OVC deck of high clouds with cigs near or greater than 15kft will continue across the terminals through 12 UTC/SAT supporting VFR conditions. A weakening band of showers is pushing northwestward from the coastal low but latest radar shows these showers weakening considerably so removed any shower mention from the PSF and POU TAF through sunrise. Then, a few additional showers look to return between 14 and 21 UTC. While most showers should be light and not obstruct visibility, included a TEMPO group for MVFR vis at PSF, POU and ALB as there is a low chance that showers become steady enough to reduce vis. Steadier periods of rain associated with the incoming nor'easter push inland from east to west towards the end of the TAF period continuing after 06 UTC/SUN. This period of rain will likely lead to a prolonged period of MVFR vis/cig and potentially even IFR vis depending on the intensity.

North to northeast winds will remain a bit breezy through 12 UTC at ALB, PSF and POU sustained 5 - 10kts with gusts up to 20kts at PSF. Winds strengthen by 14-15 UTC with sustained winds 10-15kts and gusts up to 20-30kts at all terminals through the end of the TAF period. The strongest gusts will continue to be at KPSF/KPOU where there is the highest chance for gusts to reach 30kts. Introduced LLWS at PSF towards the end of the TAF period as well as winds at 2kft reach 50kts.

Outlook...

Sunday Night: High Operational Impact. Definite RA...TSRA. Monday: High Operational Impact. Definite SHRA...RA. Monday Night: Moderate Operational Impact. Chance of SHRA. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: No Operational Impact. NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: Low Operational Impact. Slight Chance of SHRA.

ALY WATCHES/WARNINGS/ADVISORIES

CT...Wind Advisory until 8 AM EDT Sunday for CTZ001-013. NY...None. MA...None. VT...None.